Scientists find stress linked to acne

BERLIN, GERMANY (CNN) --It's a common experience: You're under stress because of an exam, your job or just juggling your everyday activities -- and you develop acne.

Was the outbreak caused by stress? Until now, no scientific evidence has supported that it is.

But German researchers say they have found a major indication that stress and acne, as well as other skin conditions, are linked.

"At the beginning we thought this was a crazy hypothesis, that something connected to the central nervous system could have anything to do with the skin," said Christos Zouboulis, a professor at the Free University in Berlin.

Acne forms when oily secretions from the sebaceous glands beneath the skin plug up the pores. But what causes the oil to form in the first place? The German researchers found that a stress hormone called corticotropin-releasing hormone (CRH) is released in the sebaceous gland -- producing oily skin, which sets the stage for acne.

Zouboulis says at this point it's difficult to say if stress actually causes the acne or just exacerbates the condition.

Dr. Jerome Litt, a dermatologist who's been in practice for more than 50 years and wrote the book "Your Skin From A to Z", says he firmly believes stress aggravates acne.

"But a lot of well-known dermatologists refuse to believe it," said Litt. "I believe in tough situations there's an increase in testosterone and androgens -- male hormones -- and the increase in oil accounts for acne."

The German researchers say they also have evidence from studies in mice that the CRH contributes to the hair loss seen in male pattern baldness.

"We may be coming close to understanding the mechanism that makes hair fall out," said Zouboulis. "We're finding the skin can regulate normal and abnormal situations more than we thought before, so what's happening in the central nervous system affects the skin."